Chemical properties, microbial respiration, and decomposition of coarse and fine particulate organic matter
Chemical properties, microbial respiration, and decomposition of coarse and fine particulate organic matter
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化学性质、微生物呼吸以及粗颗粒和细颗粒有机物的分解
DOI：
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发表时间：
2008
影响因子：
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通讯作者：
H. Furumai
中科院分区：
文献类型：
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作者：
C. Yoshimura;M. Gessner;K. Tockner;H. Furumai
摘要细颗粒有机物（FPOM）是河流食物网的重要组成部分，为各种生物提供了重要的资源。我们的目标是阐明FPOM动力学通过确定化学性质，微生物呼吸，和原位分解率的不同FPOM馏分的父粗颗粒有机物（CPOM）。通过将5种类型的CPOM喂给切碎的端足类动物（钩虾属），生产出具有规定质量的FPOM（100-500 μm）：木材，丝状绿色藻类，以及白蜡树，桤木和橡树的调理叶。不同来源的钩虾均质化POM在木质素和养分含量方面的摄食和排便。FPOM的木质素含量（20.5-45.6%）高于亲本CPOM（5.7-26.8%），而在CPOM（12-109）转化为FPOM（10-34）的过程中，摩尔C：N降低。在叶片衍生的FPOM上的微生物呼吸速率（0.13-0.45 mg O2 g−1 C h−1）低于在母体CPOM上测量的速率（0.37-0.80 mg O2 g−1 C h −1）。此外，在溪流中，超过2个月的微生物分解叶衍生的FPOM（k < 0.0015/d）比母体CPOM（k = 0.0013-0.0049/d）慢，这种模式导致微生物呼吸和分解速率之间的正相关性。总的来说，我们的数据表明，CPOM转化为FPOM对降低C质量具有抑制作用，这反过来又降低了微生物活性和分解速率。
Abstract Fine particulate organic matter (FPOM) plays a critical role in structuring and sustaining stream food webs by providing an essential resource for various organisms. Our goal was to elucidate FPOM dynamics by determining chemical properties, microbial respiration, and in situ decomposition rates of different FPOM fractions in relation to the parent coarse particulate organic matter (CPOM). FPOM (100–500 μm) of defined quality was produced by feeding 5 types of CPOM to shredding amphipods (Gammarus spp.): wood, filamentous green algae, and conditioned leaves of ash, alder, and oak. Feeding and defecation of Gammarus homogenized POM of the different origins in terms of proximate lignin and nutrient content. FPOM had higher lignin content (20.5–45.6%) than did parental CPOM (5.7–26.8%), whereas molar C:N decreased during the conversion of CPOM (12–109) to FPOM (10–34). Microbial respiration rates on leaf-derived FPOM were lower (0.13–0.45 mg O2 g−1 C h−1) compared to rates measured for parent CPOM (0.37–0.80 mg O2 g−1 C h−1). Furthermore, microbial decomposition over 2 mo in a stream was slower for leaf-derived FPOM (k < 0.0015/d) than for the parent CPOM (k = 0.0013–0.0049/d), and this pattern resulted in a positive correlation between rates of microbial respiration and decomposition. Overall, our data indicate that transformation of CPOM to FPOM has a homogenizing effect toward lower C quality, which, in turn, reduces microbial activity and decomposition rate.